I think it’s worth noting that the priapism in the study is “high-flow” priapism, which I presume means that the blood is not actually locked in the penis, and that on the contrary, freshly oxygenated blood is coming in at all times. This would remove the major risk of normal priapism. In the single case the doctor reports on, a 13 year old had grown a penis slightly longer and far thicker than most adults after 4 years of having a constant erection. If the same principle could be applied to an adult, this could be promising. Since the doctor seems to regard high-flow priapism as having a straightforward cause, and a simple cure, it might potentially be induceable. (Given that the cause is nerve damage to a specific nerve, this seems dangerous with our current understanding of the nervous system. I fully expect that within the next ten to twenty years we’ll have the undestanding necissary to do this deliberately, though.)